Here we describe the performance and further development of a
directional fast neutron detection system: the Neutron Time
Projection Chamber (nTPC). Fast neutron detection shows
significant promise as a special nuclear material (SNM) search
method. Directionally sensitive detection offers improvement in
detection speed compared to proximity searching, powerful
suppression of backgrounds, and the ability to map multiple or
distributed sources. The nTPC provides an efficient means of
measuring the full 3D trajectory, specific ionization (i.e
particle ID) and energy of charged particles and is optimized to
measure recoil protons from fast neutron scatters in hydrogen or
methane gas. Here, we describe detector performance, which
includes clearly observing and localizing a fission source at 10s
of meters standoff along with the ability to resolve multiple
fission sources.

*This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Security, LLC, Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2011.APR.K1.31